This invention relates to a color image-formable material suitable for preparing a color proof for color correction in color printing, a process for preparing the same and a method of forming a transferred image using the same, particularly to a color image-formable material by which a color proof more approximate to a print can be obtained, a process for preparing the same and a method of forming a transferred image using the same.
It has been well known in this field of the art that a color sheet (also called a color proof) for color correction is used for the purpose of saving labor and time for proof printing which is carried out as a previous step of final printing in multicolor printing.
As a method of forming a multicolor transferred image by using a color sheet for color correction, there may be mentioned, for example, a direct transfer method in which a color image is directly transferred to and laminated on a final image-receiving paper described in Japanese Provisional Patent Publication No. 41830/1972, an indirect transfer method in which a color image is temporarily transferred to a temporary (image-receiving) sheet described in Japanese Provisional Patent Publications No. 97140/1984 and No. 189535/1986 and a method of repeating steps of transferring a color light-sensitive layer to an image-receiving paper and then forming an image described in Japanese Provisional Patent Publication No. 50127/1981.
In all of the methods described above, the surface of an image-receiving material on which an image is formed is covered with an organic polymer layer so that gloss of the surface of the resulting image is too high, whereby there is a problem of giving an impression different from quality of an image obtained by final printing. Particularly in the method of Japanese Provisional Patent Publication No. 189535/1986, a non-image portion is covered with an organic polymer layer (a polymer layer), whereby there is a problem that inherent gloss and feel of a material cannot be obtained.
In order to solve the above problems, there has been proposed a method in which only a color image is transferred to and laminated on an image-receiving material to obtain a multicolor image (Japanese Provisional Patent Publication No. 48248/1991). In this method, an image-receiving material is not covered with an organic polymer layer so that in principle, it is possible to obtain an image extremely approximate to quality of an image obtained by final printing. The present inventors have found that in a color image-formable material used in the method of transferring only an image portion, only an image is transferred from a heat-softening layer (a cushion layer) to an image-receiving layer at the time of heat lamination so that there is a problem that uniformity of coating and also uniformity of an image portion density may be sometimes impaired by convex portions formed by gellation of a resin in the cushion layer, whereby approximation of a print is impaired.